National Weather Service Hydrologic Program in Alaska Larry Rundquist Alaska-Pacific River Forecast Center National Weather Service National Oceanic and Atmospheric Administration

Mission Statement National Weather Service (NWS) is a federal agency within National Oceanic and Atmospheric Administration (NOAA), which is part of Department of Commerce (DOC) National Weather Service Mission Statement " The National Weather Service (NWS) provides weather, hydrologic, and climate forecasts and warnings for the United States, its territories, adjacent waters and ocean areas, for the protection of life and property and the enhancement of the national economy. NWS data and products form a national information database and infrastructure which can be used by other governmental agencies, the private sector, the public, and the global community. " In support of this NWS mission, the Alaska-Pacific River Forecast Center (APRFC) produces timely and accurate water forecasts and information using the best available scientific principles to integrate and model water, weather, and climate information. Our highly-motivated, customer-focused staff is dedicated to professionalism, innovation, and fulfilling expectations of our customers and partners.

NWS AR Hydrologic Program

APRFC Responsibilities Non-operational support for hydrologic program in NWS Pacific Region APRFC is one of 13 RFCs

APRFC Staff 1 Alaska Regional Hydrologist/Hydrologist in Charge 1 Service Coordination Hydrologist 1 Development and Operations Hydrologist 2 Senior Hydrologists 1 Hydrologists 1 Senior HAS Forecaster 2 HAS Forecasters 1 Hydrologic Technician HAS – Hydrometeorological Analysis and Support

Data Collection A very important hydrologic function in the RFC and the WFO’s is the collection of data from observers Data can be entered using HydroDisplay or the web entry form It is very important to capture the remarks as well as the data Remarks are entered into the River Notes database

River Notes Database Database entry and search are available on the intranet

River Notes DB Rules Enter all relevant observations, especially those related to ice, river, debris, weather, and related conditions Use general references rather than names since the notes are available on the internet Begin entry with PIREP if the information is from a pilot report (directly or indirectly) Begin entry with INTERNAL if the information contains names, phone numbers, product issuance information, or other non-public information Split out public and INTERNAL information into two entries to maximize the information provided to the public

Flooding Sources Flooding due to Excessive Runoff Snowmelt Glacier melt Rainfall Flooding due to Ice Blockage Freeze-up Ice Jams Aufeis (Naled) Breakup Ice Jams Blocked culverts Other Flood Hazards Jokulhlaups (Glacier Dammed Lake Releases) Dam break or Geologic Control Coastal Flooding Tsunami

River Gauges River gauge network is sparse Stages (levels) based on arbitrary datum Flood stage defined at many sites Discharge (flow) is volume of moving water Rating curve is link between stage and flow

Automated River Gauges Operated by USGS, USFWS, BLM, NWS, ADNR and UAF Components include sensor, data collection platform (DCP), and telemetry (optional) Telemetry methods include telephone, satellite, and meteorburst Need more gages in Alaska

Manual River Gauges Most are read by observers for the NWS Typically read once per day in the morning Types include wire weight, staff gauge, and slope profile

Flood Stage ■Flood Stage - an established gage height at a given location above which a rise in water surface level is defined as a flood for the corresponding river or stream reach. ■Flood Categories - terms used to describe or categorize the severity of flooding on rivers and streams. ■Minor flooding - minimal or no property damage, but possibly some public threat or inconvenience (5-10 yr recurrence interval event). ■Moderate Flooding - some inundation of structures and roads near stream. Some evacuations of people and/or transfer of property to higher elevations is necessary (15-40 yr recurrence interval event). ■Major Flooding - extensive inundation of structures and roads. Significant evacuations of people and/or transfer of property to higher elevations ( yr recurrence interval event). ■Record Flooding - flooding which equals or exceeds the highest stage or discharge at a given site during the period of record keeping.

Flood Products

Product Title and Purpose for Issuance Flood Products ■Flood Potential Outlook - Possibility of flooding identified several days to months in advance ■Flood Watch - Possibility of flooding identified hours to days in advance ■Flash Flood Warning - Fast rising stream that is rising to moderate or major flood level ■Flood Warning - Slow responding stream that is rising to moderate or major flood levels ■Flash Flood Statement - Update of flash flood warning with new information ■Flood Statement - Update of flood warning with new information or as “Flood Advisory” for minor or nuisance flooding with no significant threat to life/property

Non-Flood Hydrologic Products ■River Statement - In-bank rise; other notable condition such as debris - no flooding ■River Forecasts for Alaska - Daily summaries of current and forecast river stages on major drainages in four regions. Issued daily from May through October ■River Recreation Statement - A product highlighting river levels, trends, and water clarity for recreational users...generally for the high- use areas around Southcentral Alaska. Issued daily at 0130Z (4:30 p.m. local) from May through October ■Hydrometeorological Discussion - Daily narrative of hydrometeorological and hydrologic conditions in Alaska. Issued at 2300Z (3:00 p.m. local) daily from May through October, each Thursday from December through March, and each Monday, Wednesday, and Friday in November and April

Hydrologic Products Internet Access

APRFC Operations Open-Water Season Winter season is used for weather monitoring and development projects

HAS Forecaster Duties Weather and river self-briefing Quality control of precipitation data Prepare HYD Bulletin Prepare a quantitative precipitation estimate (QPE) map Review meteorological models Prepare quantitative precipitation forecast (QPF) products Recently added temperature and freezing level forecasts Prepare Hydrometeorological Discussion text product Prepare Flood Outlook graphical products Monitor ongoing weather

HAS Precipitation Products Gridded QPE and QPF Products

HAS Information on Intranet

6-hr QPF Product out 60 hrs

Graphical HMD Hydrometeorological Discussion ■Seasonally several snow information maps ■Quantitative precipitation estimate ■Quantitative precipitation forecast 0-24 hrs ■Quantitative precipitation forecast hrs ■Current hazards & public forecasts ■Freezing levels ■Radar image ■Satellite image ■River gauge map Current snapshot of images that link to full size image

Hydrologist Duties Check data ingest and processing Weather and river self-briefing Quality control of river stage data Maintain hydrologic models –Adjust model input & parameters to match observed stages for each modeled segment using run-time mods –Incorporate HAS QPF and forecast temperature values Prepare river forecast products

Hydrologist Duties Review HAS products for the area Tune hydrologic model – Adjust model input & parameters to match observed stages for each modeled segment – Incorporate HAS QPF and forecast temperature values Fine-tune forecast values Prepare forecast 6-hr time series numerical product (RVF) Prepare text forecast products (RVA) – Ingest numerical forecast values – Prepare forecast trends for non-numeric forecast points Tasks done for each of the four regional text forecasts:

NWSRFS

Modeling the Tanana River Basin

Hydrologic Model in JNU HSA Basins to be added this year include TYAA2 Taiya River SKGA2 Skagway River ALKA2 Alsek River TKUA2 Taku River And next year STKA2 Stikine River will be added

Snowpack Simulation

APRFC Main Page

Google Map Data Display

Web Hydrograph

Ensemble of Hydrographs

Probability of Flooding Conditional Simulation Historical Simulation

Weekly Maximum Flows

Follow progress of breakup on Alaska Weather on PBS or on web

The End Please contact us if you have further questions about our operations